Trixi的菜园:矩形面积与代数分割
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本范例演示如何将一个矩形菜园按不同方式分割成四个子矩形并求面积。学生通过两种方法计算7 m×4 m菜园的面积,使用变量a、b、c、d表示边长并写出面积公式;进一步在8 m×5 m菜园中按长度1∶3、宽度2∶3的比例划分。涉及的核心数学概念包括矩形面积、比例分配以及代数式的展开、合并与提取公因式。构造上使用GeoGebra的Segment、Point、Textfield、LaTeX、If、Rotate等命令,配合输入框与判题对象实现交互。适合七至八年级学生练习代数变形与几何面积的综合性任务。
GeoGebra 命令及参数
IndexOf("$\textsf{Länge\vphantom{Öj}}$", DropDown4) → correct4numSelectedIndex(DropDown4) → input4Point(Line[Beet1, v]) → Beet2Point(Translate[Segment[Beet2, Beet2 + ((2 / 5 * beetx), 0)], vschaufel]) → Schaufel1Flatten(Sequence[Sequence[Beet1 + (m * (beetx / 5, 0)) + (j * (0, beety / 4)), m, 1, 6], j, 1, 3]) → listpointsPoint(listpoints) → TPointSegment((x(Beet5), y(Beet1)) + (streckenabs, 0), (x(Beet5), y(TPoint)) + (streckenabs, 0)) → syRUSegment((x(Beet5), y(Beet5)) + (streckenabs, 0), (x(Beet5), y(TPoint)) + (streckenabs, 0)) → syROElement({1, 2, 3, 4, 5, 6, 7, 7.1, 9, 10, 11, 12, 13, 14, 15}, step2) → stepTextfield(input1) → Eingabefeld1Textfield(input2) → Eingabefeld2Point(Line[Garten1, xAxis]) → Garten2Point(Line[Trixi1, xAxis]) → Trixi2Textfield(input3) → Eingabefeld3Textfield(input0) → Eingabefeld0Point(Line[Beet3, xAxis]) → Beet3bPoint(Translate[Translate[Segment[Beet2, Beet2 + ((2 / 5 * beetx), 0)], vschaufel], vschaufel2]) → Schaufel2Textfield(input5) → Eingabefeld5Textfield(input6) → Eingabefeld6Textfield(input7) → Eingabefeld7Textfield(input8) → Eingabefeld8Textfield(input9) → Eingabefeld9Textfield(input10) → Eingabefeld10Textfield(input11) → Eingabefeld11Point(Line[Trixi3, xAxis]) → Trixi4LaTeX(step, true, true) → Text35Textfield(input12) → Eingabefeld12Textfield(input13) → Eingabefeld13Textfield(input14) → Eingabefeld14Textfield(input15) → Eingabefeld15If(step ≟ 2, {Polygon[Beet1, (x(Beet1), y(Beet5)), Beet5, (x(Beet5), y(Beet1))]}, {Polygon[Beet1, (x(Beet5), y(Beet1)), (x(Beet5), y(TPoint)), (x(Beet1), y(TPoint))]}) → beetATextfield(input16) → Eingabefeld16Textfield(input17) → Eingabefeld17Textfield(input18) → Eingabefeld18Textfield(input19) → Eingabefeld19Segment(Beet1 + (0, -0.8), (x(Beet5), y(Beet1) - 0.8)) → sxUSegment(Beet1 + ((-streckenabs), 0), (x(Beet1), y(TPoint)) + ((-streckenabs), 0)) → syLUSegment((x(Beet1), y(Beet5)) + ((-streckenabs), 0), (x(Beet1), y(TPoint)) + ((-streckenabs), 0)) → syLOSegment(Beet1 + (0, (-streckenabs)), (x(TPoint), y(Beet1)) + (0, (-streckenabs))) → sxULSegment((x(TPoint), y(Beet1)) + (0, (-streckenabs)), (x(Beet5), y(Beet1) - streckenabs)) → sxURSegment(Beet5 + ((6 * streckenabs), 0), (x(Beet5), y(Beet1)) + ((6 * streckenabs), 0)) → syRASegment((x(Beet1), y(Beet5)) + (0, streckenabs), (x(TPoint), y(Beet5)) + (0, streckenabs)) → sxOLSegment((x(TPoint), y(Beet5)) + (0, streckenabs), (x(Beet5), y(Beet5) + streckenabs)) → sxORSegment(Beet5 + (streckenabs, 0), (x(Beet5), y(Beet1)) + (streckenabs, 0)) → syRIRotate(Segment[ArrowCenter + (ArrowDistance, 0), ArrowCenter + (ArrowDistance + ArrowLength, 0)], ArrowAngle + ((1 - 1) * (360°) / ArrowNumber), ArrowCenter) → arrow1Rotate(Segment[ArrowCenter + (ArrowDistance, 0), ArrowCenter + (ArrowDistance + ArrowLength, 0)], ArrowAngle + ((2 - 1) * (360°) / ArrowNumber), ArrowCenter) → arrow2Rotate(Segment[ArrowCenter + (ArrowDistance, 0), ArrowCenter + (ArrowDistance + ArrowLength, 0)], ArrowAngle + ((3 - 1) * (360°) / ArrowNumber), ArrowCenter) → arrow3Rotate(Segment[ArrowCenter + (ArrowDistance, 0), ArrowCenter + (ArrowDistance + ArrowLength, 0)], ArrowAngle + ((4 - 1) * (360°) / ArrowNumber), ArrowCenter) → arrow4PointIn(Circle[Pos5, 3]) → Kklein1aPoint(Circle[Kklein1a, 1.7]) → Kklein1bPointIn(Circle[Pos5, 4]) → Sklein1aPoint(Circle[Sklein1a, 1.5]) → Sklein1bCorner(PicBeetStep8, 3) → Beet4Segment((x(Beet3), y(Beet4)) + ((0.2 * streckenabs), streckenabs), (x(Beet4), y(Beet4)) + ((-0.2 * streckenabs), streckenabs)) → bxOSegment((x(Beet3), y(Beet3)) + ((0.2 * streckenabs), (-streckenabs)), (x(Beet4), y(Beet3)) + ((-0.2 * streckenabs), (-streckenabs))) → bxUSegment((x(Beet4), y(Beet4)) + (streckenabs, (-0.3 * streckenabs)), (x(Beet4), y(Beet3) + (0.73 * (y(Beet4) - y(Beet3)))) + (streckenabs, (0.3 * streckenabs))) → byOSegment((x(Beet4), y(Beet3) + (0.73 * (y(Beet4) - y(Beet3)))) + (streckenabs, (0.3 * streckenabs)), (x(Beet4), y(Beet3)) + (streckenabs, (0.3 * streckenabs))) → byUSegment((x(Beet4), y(Beet4)) + ((5.5 * streckenabs), (-0.3 * streckenabs)), (x(Beet4), y(Beet3)) + ((5.5 * streckenabs), (0.3 * streckenabs))) → byRPointIn(Circle[Pos13, 3]) → Kklein2aPointIn(Circle[Pos13, 5]) → Sklein2aPointIn(Circle[Pos13, 9]) → Bklein1aPoint(Circle[Bklein1a, 1]) → Bklein1bPointIn(Circle[Pos13, 9]) → Tklein1aPoint(Circle[Tklein1a, 1.3]) → Tklein1bPoint(Circle[Kklein0a, 1.7]) → Kklein0b